The present invention is directed to an audience response system for retrieving user responses entered into handheld response units and a method of retrieving audience responses and, in particular, to such a system and method utilizing a frequency agile transmission protocol.
Wireless response systems are capable of retrieving responses from a large number of users wirelessly. Such systems may operate on a fixed frequency or may utilize a variety of frequencies. The latter is known as a frequency agile system. An example of a frequency agile system is a spread-spectrum frequency hopping protocol, such as the type disclosed in commonly assigned U.S. Pat. Application Publication No. 2004/0229642 A1 entitled WIRELESS POLLING SYSTEM USING SPREAD-SPECTRUM COMMUNICATION, the disclosure of which is hereby incorporated herein by reference. However, other types of frequency agile protocols are known.
International Patent Application Publication No. WO 2006/041743 A2 entitled RESPONSE SYSTEM AND METHOD WITH DYNAMIC PERSONALITY ASSIGNMENT, which is commonly assigned with the present application, discloses a response system and method in which the base unit is capable of assigning personality data to the response units in order to facilitate communication between the response unit and the base unit. The personality data, which may include, for example, a timeslot in which the particular response unit is assigned, may be sent upon request by the response unit to “join” that base unit. At the beginning of a voting session, it may be necessary for a large number of response units to send join requests to the base unit and to receive personality data from the base unit.
The base unit may communicate various types of information with the response units. In certain systems, the base unit sends out polling packets to retrieve response data from the response units. However, in other systems, the response units transmit asynchronously without the necessity for a transmission from the base unit. Regardless of the type of system, the base unit may be capable of transmitting other information to the response units. Examples of such other information include global message packets and firmware download packets. It may also include test question tables to be displayed at the response units. It also may include configuration data and login data for the particular response units. It may also include acknowledge signals of the type disclosed in commonly assigned U.S. Pat. No. 5,724,357 entitled REMOTE RESPONSE SYSTEM AND DATA TRANSFER PROTOCOL.